A new methodology for the estimation of wheel–rail contact forces at a high-frequency range

Abstract

Online measurement of wheel-rail contact forces is nowadays in demand for evaluating safety and manoeuvring the condition in real time and in real operation. In this study, the wheel-rail contact forces are estimated using a novel indirect identification method based on the measured radial strain on the wheel web. Further, the strain response of the rolling wheel is derived using an analytical solution of the disk under a rotating load, and a scheme was prepared for the identification of the rolling wheel parameters and its corresponding characteristic matrix. An appropriate angular strain configuration is employed to eliminate the effect of wheel rotation. The Tikhonov regularization technique is employed to solve the ill-posed least square problem and to attenuate the effect of noisy measurement and numerical uncertainty during the estimation of the forces. A finite element model of the rotating load is then constructed to investigate the effectiveness and accuracy of the proposed methodology. The effects of the rotating speed, loading and measurement noise on the estimated normal force are studied. It is found that neglecting the effect of the rotating speed causes a notable error particularly in the high-speed range.

Thermal imaging of the wheel-rail interface

“…The latest force measurement methods at the wheel-rail interface are based primarily on the use of strain gauges placed peripherally on the wheel rim. [11][12][13][14][15][16][17] Other methods of estimating contact forces are based on the analysis of the values of vibration acceleration as input data for inverse mathematical models 18,19 or on wheel strain measured with the use of distance transducers. 20 The issue that seems interesting and potentially feasible is the identification of the conditions of the wheel-rail interaction corresponding to the conditions of the generation of flanging and squealing noise, with the use of thermal imaging.…”

“…The latest force measurement methods at the wheel-rail interface are based primarily on the use of strain gauges placed peripherally on the wheel rim. 11–17 Other methods of estimating contact forces are based on the analysis of the values of vibration acceleration as input data for inverse mathematical models 18,19 or on wheel strain measured with the use of distance transducers. 20…”

Wheel-Rail Force Measurement Based on Wireless LC Resonance Sensing

“…The resonant frequency fres of the LC resonance sensor, determined by Leq and C, is derived as Equation (8). Through LDC's frequency counter, the resonant frequency can be measured and thus the inductance is determined.…”

A Novel Methodology for Dynamic Weigh in Motion System for Railway Vehicles With Traction

“…Similar to the WIM systems reported in previous paragraph, contact force estimation systems use force sensitive elements (e.g. strain gages) and in this case, instead of replacing such elements to the track, bridge or sleepers, they are replaced to the wheel, [24], [25]. However, as stated in [26], the use of such systems is not suitable for commercial vehicles since tread braking of wheelsets equipped in this way is generally impossible due to the sensitivity of strain gages and similar elements to the generated heat.…”